(Health.com) -- Amid the highest unemployment rate in recent decades and massive job losses around the country, most workers feel happy to at least be employed. What they aren't feeling, however, is healthy.

People whose work-life balance is off may be cutting back on important components of a healthy lifestyle.

One in three workers has at least one symptom of clinical depression; 41 percent say they feel stressed sometimes, often, or very often; and one in five has trouble falling asleep often or very often. In all, 14 percent are being treated for high cholesterol and one in five is taking blood-pressure-lowering medication.

In fact, the percentage of workers who say they're in excellent health has dropped from 34 percent in 2002 to 28 percent in 2008, according to a report recently released by the Families and Work Institute (FWI), a nonprofit research company.

"When we try to explain what happened [since 2002], it wasn't what we thought was the simple answer -- that the population is getting older and younger people simply have better health," says Ellen Galinsky, the FWI's president and cofounder. "It was a change among men and higher income employees [due to] the uncertainty around the economy and the greater pressure that people are feeling to manage their work and family life." Health.com: 7 daily habits that can halt heartburn

Some workplaces are healthier than others

Not all workplaces are created equal when it comes to health. In fact, 38 percent of workers at certain jobs -- called "effective" workplaces in the report -- were much more likely to say they were in excellent health. Conversely, only 19 percent of employees in workplaces with a low effectiveness rating reported being in excellent health. Health.com: Stop feeling bad about feeling good

So what makes an effective workplace? Six factors make a difference, Galinsky says. Workers may feel healthier if they have "learning opportunities and challenge, a good fit between work and personal life, autonomy, having a supervisor who supports job success, economic security -- no surprise in this economy -- and a work climate of respect and trust," she says.

Eric Endlich, Ph.D., a Massachusetts-based clinical psychologist who specializes in workplace health, says these factors can make people feel in control of their destiny, challenged but not stressed, and appreciated.

"If someone is stressed at work from [feeling like they lack in] any of these factors, they could have a higher pulse, hypertension, [and] higher blood pressure, and if these things happen chronically they can worsen as well as worsen an existing condition," he says. Health.com: Feeling stressed? Why you may feel it in your gut

Feeling a lack of control in the workplace or not enough support from a supervisor may lead to feelings of helplessness, says Endlich, which in turn can spiral into depression, "which is associated with lots of poor health outcomes [and] increases mortality rates from all causes," he says. Health.com: 10 best big cities for people with asthma

According to the report, one of the biggest predictors of feeling healthy is a balance between work and personal life. "If someone has difficulty with this balance," says Endlich, "then they're going to be cutting back wherever they can," including on important components of a healthy lifestyle, like getting enough sleep, shopping for and preparing healthy food, and exercising.

What employers--and employees--can do

It's a tough economy, and many employers may feel that they have no choice but to cut corners. For example, the researchers found that employees with paid sick days and more paid vacation days reported better health. Although these options may cost employers, there are other things employers can do -- such as promoting a respectful work environment -- to become more effective workplaces. "It's important to know that having an effective workplace doesn't [have to] cost employers any money," says Galinsky. "It's as simple as how people treat each other." Health.com: 10 easy food swaps cut cholesterol, not taste

Galinsky suggests that bosses who can't afford to offer extra vacation days should put themselves in their workers' shoes and imagine how employees would want to be treated. She encourages managers to talk calmly and respectfully to workers and implement greater flexibility in hours to help them manage their personal lives.

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Allowing employees to work earlier or later could even benefit the company, for example, by extending hours of business or productivity each day. It can also help to survey employees and listen to their suggestions, which can bolster employees' feelings of control, says Endlich.

Employees can take matters into their own hands too. Half of the workers in the survey didn't exercise regularly, and 25 percent smoked. In 2002, 21 percent were obese, but by 2008, that number had jumped to 26 percent. So taking charge of your health outside of the workplace is a good place to start.

"We have this image of work as a marathon; you're always running a race and can never stop," Galinsky says. This marathon, just like running, takes a physical toll, leading to the health problems prevalent among American workers.

"The image of work as weight lifting is better," she says. "Having some time for rest and relaxation is important."

The survey, which is updated every five years, focused on about 2,800 workers who were salaried or paid on an hourly wage basis.